S-Band GW-Level Relativistic Magnetron Operating at Relatively Low Applied Voltage

To realize miniaturization of high-power microwave (HPM) systems, a high-efficiency GW-level relativistic magnetron (RM) operating at a relatively low applied voltage is presented, which does not require a large high-energy pulsed power source. An eight-cavity anode block with rectangular vanes is adopted. The resonators in the anode block, where the high-frequency energy is directly stored, are enlarged by introducing rectangular vanes. The microwave extraction is accomplished by a step-like diffraction output, which benefits the compact magnet system design. In experiments, several transparent cathodes have been employed to investigate the cathode effects on the magnetron performance, including cathode configurations, cathode endcaps, and emission length. With the optimal cathode, the proposed RM can radiate microwave power of 1.1 GW with a power conversion efficiency of 51% at 2.72 GHz when the applied voltage is around 380 kV and the axial magnetic field is 0.44 T.